Anselm of Canterbury describes the reason for the devil's fall in his ("On the Devil's Fall"). Breaking with Augustine's diabology, he absolved God from pre-determinism and causing the devil to sin. Like earlier theologians, Anselm explained evil as nothingness, or something people can merely ascribe to something to negate its existence that has no substance in itself. God gave the devil free will, but has not caused the devil to sin by creating the condition to abuse this gift. Anselm invokes the idea of grace, bestowed upon the angels. According to Anselm, grace was also offered to Lucifer, but the devil willingly refused to receive the gift from God. Anselm argues further that all rational creatures strive for good, since it is the definition of good to be desired by rational creatures, so Lucifer's wish to become equal to God is actually in accordance with God's plan. The devil deviates from God's plans when he wishes to become equal to God by his own efforts without relying on God's grace. Anselm also played an important role in shifting Christian theology further away from the ransom theory of atonement, the belief that Jesus' crucifixion was a ransom paid to Satan, in favor of the satisfaction theory. According to this view, humanity sinned by violating the cosmic harmony God created. To restore this harmony, humanity needed to pay something they did not owe to God. But since humans could not pay the price, God had to send Jesus, who is both God and human, to sacrifice himself. The devil does not play an important role in this theory of atonement any longer. In Anselm's theology, the devil features more as an example of the abuse of free will than as a significant actor in the cosmos. He is not necessary to explain either the fall or the salvation of humanity. History Early Christianity The notion of fallen angels already existed, but had no unified narrative in Pre-Christian times. In 1 Enoch, Azazel and his host of angels came to earth in human shape and taught forbidden arts resulting in sin. In the Apocalypse of Abraham, Azazel is described with his own (Magnificence), a term usually used for the Divine in apocalyptic literature, already indicating the devil as anti-thesis of God, with the devil's kingdom on earth and God's kingdom in heaven. In the Life of Adam and Eve, Satan was cast out